Manufacture of artificial silk



UNITED STATES PATENT OFFICE.

EMILE BRONNERT, 0F MULHAUSEN, FRANCE.

MANUFACTURE OF ARTIFICIAL SILK.

1 387,882. No Drawing.

To all w 110m it may concern:

Be it known that I, EMILE BRONNERT, a citizen of the Republic of France,residing at 1 Quai du Barrage, Mulhausen, Alsace Lorraine, France, haveinvented certain new and useful Improvements in or Relating to theManufacture of Artificial Silk, for which I have filed applications inGermany,

May 19, 1919; France, Apr. 7, 1920; Netheracid, provided that the actionof the acid is not too violent.

Instead of adding sulfates in such quantities that the ionization of theacids is rendered ineffective (that is beyond the bisulfate proportionor an acid concentration of about 20%), it is preferable to use arelatively weak acid (about 10% concentration), while the decomposingpower is fur ther restricted by the briefness of the action of the acid,so that even at somewhat increased temperature of the latter, it canhave no appreciable bad influence on the thread. The strong coolingtaking place during the emergence of the thread from the "bath and thecomparatively long distance it has to travel to the receiving member, is

1' very advantageous.

- obtained with Now, I have-found that with sulfuric acid 7 alone (at atemperature of about 45 Celsius), 40

and with the usual spinning length of 150- mm, a soft full-bodied threadcan be great certainty, even with viscose of widely difi'erent ages,provided sulfuric acid be used which is wholly or partially bound toaromatic radicals.

-My' invention is illustrated by the following examples.

Emample 1.

The spinning bath consists of a solution gr. sulfuric acid monohydrateper liter. This solution can of 45 for spinning raw viscose of the usualcomposition through the usual nozzles of 0.10 mm. diameter bycalculating the feed of spinning solution corresponding to aSpecification of Letters Patent.

.while fresher viscose 100 gr. sodium benzenesulfonate and 120' be usedat a temperature Patented Aug. 16, 1921.

Application filed September 2, 1920. Serial No. 407,753.

drawing speed of 45 m. per minute and the number of nozzle apertures toan individual thread strength of about 7 deniers.

ith ripenesses of 6 (chlorid of ammomum standard) up to ripenesses ofabout 9, there are obtained perfectly fine, soft, fullbodied, highlylustrous threads of good tenacity and elasticity.

With fresher viscose, however, of about 12 ripeness not a hi hlylustrous, but only a matt or dull three is obtained, but, nevertheless,not the lusterless cotton-like prod not which is otherwise occasionallyobtained when the degree of ripeness of the viscose and the degree ofacidity of the bath are not brought into proper relation.

Example 2.

12, excellent, soft, full-bodied threads are obtained.

It was observedthat riper viscose has the tendency to yield a somewhatfirmer but somewhat less elastic or stretchable silk, gives a somewhatless the more elastic thread, present'case up to 18% firm, but hence allfor instance in the and more.

By varying the degree of ripeness it is therefore possible to re -ulatethe expansibility of the threads w ich is so essential for weavingpurposes.

Instead of sodium benzenesulfonate there can also be used the directsulfonation mixture of the benzene or of its homologues, its oxyor otherderivatives, or of the condensation products thereof, and when I speakon my claims of sodium benzenesulfonate, I mean to include the abovementioned homologues, condensation products or derivatives.

Owing to the fact that it is generally unnecessary to make a separationof the various isomers formed, and that the tedious transmutation intosodium salt is not necessaryfthe process appears to be especiallyeconomical.

The process can be used for silk of the ordinary size or for very finethreads. For the latter the concentration of the free acid must be inthe well known relation to the titre of the threads.

4. A bath for treating viscose, comprising sodium benzenesulfonate.

5. A bath for treating viscose, comprising 15 a sulfonation product ofbenzene or its homologues.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

EMILE BRONNERT. Witnesses:

L. R; SE JALIs, N. SCHLUMBORGE.

